Hach Lange CL17, Instrument Manual

Page: 48 / 74

Page 46
Scheduled Maintenance
54400_maintain.fm
Section 3
Install the replacement tubing as follows:
1. Shut off sample flow to the instrument and set the POWER (I/O) switch to
OFF (O).
2. Remove the screws securing the pinch plate to the pump/valve module.
See
Section 1.9 on page 27 . Loosen in small increments, moving from
one screw to the other to allow tension to be relieved evenly. Remove
the plate.
3. Disconnect the pump tubes from the inlet and outlet fittings and discard
the tube assemblies.
4. Cut four 2-inch lengths of 1/16-inch ID tubing (white). Install one 1/16-to
1/8-barb elbow fittings in one of the 1/16-inch ID tubes (white) and
1/16-inch barb union fittings in the three remaining tubes. Although one of
the pump tubes is not used for fluid flow, it must be included to provide
even compression on all four tubes.
5. Install the two screws through the pinch plate and into the pump/valve
module. When securing the pinch plate, advance the screws in small
increments moving from one screw to the other so that the plate is drawn
down evenly. Tighten until snug, do not overtighten.
6. Set the POWER (I/O) switch to ON (I) and restore sample flow through
the instrument. Allow the instrument to run for approximately one hour to
fill the reagent lines.
3.1.3 Replacing the Analyzer Tubing
Remaining tubing in the analyzer should be replaced annually.
The maintenance kit is available with the tubing harnesses assembled
(Cat. No. 54443-01) or unassembled (Cat. No. 54443-00) If you have ordered
the unassembled maintenance Kit, use
Figure 19 and Table 3 on page 47 to
determine the tubing lengths and positions. When installing new tubing it is
helpful to dip the ends in hot water before making the connections. It also is
recommended that one tube at time be removed and replaced.
Numbers on the illustration correspond to the item numbers listed in the
legend where the size, catalog number, and quantity also are given.
The length given in
Table 3 tells how long that particular tubing segment
should be; the operator must cut a piece to that length from a coil of the
proper tubing.
The catalog number given for the tubing in the legend identifies the coil of
tubing to cut the segment from and not the number of the segment itself.
DPD Reagent tubing may darken before the scheduled replacement time but
that will not affect the performance of the instrument.